At least one example embodiment relates to a liquid storage portion for aerosol-generating systems. The liquid storage portion comprises a container for holding liquid aerosol-generating substrate and an opening for dispensing the liquid aerosol-generating substrate. The liquid storage portion is particularly suitable for handheld electrically operated vaping systems.
One type of aerosol-generating system is an electrically operated vaping system. Handheld electrically operated vaping systems are known that consist of a device portion comprising a battery and control electronics, a cartridge portion comprising a supply of aerosol-forming substrate held in a liquid storage portion, and an electrically operated vaporizer. A cartridge comprising both a supply of aerosol-forming substrate held in the liquid storage portion and a vaporizer is sometimes referred to as a “cartomizer”. The vaporizer typically comprises a coil of heater wire wound around an elongate wick soaked in the liquid aerosol-forming substrate held in the liquid storage portion. The cartridge portion may comprise the supply of aerosol-forming substrate, an electrically operated vaporizer, and a mouthpiece, on which the vaper draws.
It may be difficult to determine the remaining amount of aerosol generating substrate in the liquid storage portion of an electronic cigarette.
U.S. Pat. No. 8,528,569 B1 discloses an electrically operated aerosol-generating system comprising a liquid storage portion for storing liquid aerosol-forming substrate and an electric heater comprising a heater coil for heating the liquid aerosol-forming substrate. A wick is provided which conveys the liquid aerosol-generating substrate to the heater coil. An electric circuitry is provided, which activates the heater coil when a vaper draws a puff at the electronic cigarette. The liquid storage portion comprises a window, which allows a vaper to visually inspect the remaining fill level of the liquid aerosol-generating substrate. In order to determine the remaining fill level the electronic cigarette has to be held in a specific orientation.
It would therefore be desirable to provide an aerosol-generating system that allows a vaper to determine the remaining amount of aerosol-forming substrate in the liquid storage portion, at any time and without the need that the aerosol-generating system is held in a specific orientation.